TEN TT IR 
x 
58 ON TEN BRITISH SPECIES OF THE GENUS MNIUM. 
TABLE XXXIX. 
Number of cells of the marginal teeth. (With reference to 
M. affine and rostratum.) 
In order to test the practical value of the method, I have tried to identify 
several specimens of each species by means of the Tables XXV.-X XXVIII. 
I always succeeded, except with some specimens of M. affine and rostratum. 
These species cannot be confounded when the classic characters of the fruit 
and the inflorescence * are taken into account. But when we limit ourselves 
to the characters of the leaves, there is frequently some difficulty in the 
determination. 
Using merely the figures of the longest leaf of one fertile stem (first 
method, see $17), some specimens of both species could be determined. 
But the figures of other specimens were not decisive ; after all the tables had 
been used, I was still hesitating between affine and rostratum. Therefore 
I have recourse to a supplementary character. 
In both species, the longest leaves (10th interval) of the fertile stem are 
adorned with numerous marginal teeth, which are always simple (never in 
pairs). In M. rostratum, about the place of the greatest breadth of the 
longest leaves, the salient part of each tooth always consists of one cell 
(fig. 9: 7, 2, 3). In M. affine, at the mentioned place, the salient part of 
the teeth consists of 1, 2, 3, or even 4 cells. Among those teeth, one always 
finds some teeth the salient part of which consists of more than one cell 
(Bg. 9: 4, 5). 
All this may be shown in the form of the following table :— 
Minimum. | Maximum. 
a o 1 cell. | rostratum 1 cell. 
i os ean an LLL 1 cell. | n E Na ae ene ng 4 cells, 
* M. affine : lid of the capsule conical, apiculate ; inflorescence dioicous. 
M. rostratum: lid of the capsule with a long, straight, or curved rostrate beak ; 
inflorescence synoicous, 
See Drxon and Jameson, * British Mosses, second edition, 1904, pp. 379, 381. 
